Dual-targeting nanoparticles for in vivo delivery of suicide genes to chemotherapy-resistant ovarian cancer cells

摘要

Ovarian cancer is the most lethal gynecologic cancer. Claudin-3 and-4, the receptors for Clostridium Perfringens Enterotoxin (CPE), are overexpressed in over 70% of these tumors. Here we synthesized and characterized poly(lactic-co-glycolic-acid) (PLGA) nanoparticles (NP) modified with the carboxi-terminal binding domain of CPE (c-CPE-NP) for the delivery of suicide gene therapy to chemotherapy-resistant ovarian cancer cells. As a therapeutic payload we generated a plasmid encoding for the Diphteria Toxin subunit-A (DT-A) under the transcriptional control of the p16 promoter, a gene highly differentially expressed in ovarian cancer cells. Flow cytometry and immunofluorescence demonstrated that c-CPE-NPs encapsulating the CMV GFP plasmid (CMV GFP c-CPE-NP) were significantly more efficient than control NP modified with a scrambled peptide (CMV GFP scr-NP) in transfecting primary chemotherapy-resistant ovarian tumor cell lines in vitro (p=0.03). Importantly, c-CPE-NPs encapsulating the p16 DT-A vector (p16 DT-A c-CPE-NP) were significantly more effective than control p16 DT-A scr-NP in inducing ovarian cancer cell death in vitro (% cytotoxicity: mean ± STDV = 32.9 ± 0.15 and 7.45 ± 7.93, respectively, p=0.03). In vivo bio-distribution studies demonstrated efficient transfection of tumor cells within 12 hours after intraperitoneal (IP) injection of CMV GFP c-CPE-NP in mice harboring chemotherapy-resistant ovarian cancer xenografts. Finally, multiple IP injections of p16 DT-A c-CPE-NP resulted in a significant inhibition of tumor growth compared to control NP in chemotherapy-resistant tumor-bearing mice (p=0.041). p16 DT-A c-CPE-NP may represent a novel dual-targeting therapeutic approach for the selective delivery of gene therapy to chemotherapy-resistant ovarian cancer cells.